A known image forming apparatus includes a heater configured to generate heat and a heat receiving member configured to receive heat from the heater. The heater and the heat receiving member are configured to thermally fix a developer on a sheet. During continuous printing, heat at a central portion of the heat receiving member in a width direction thereof is lost by sheets passing thereover but the temperature at the central portion is controlled to a specified fixing temperature. As the sheets do not pass over an end portion of the heat receiving member, heat accumulates at the end portion and thus the end portion reaches elevated temperature. In this case, the temperature at the end portion of the heat receiving member (an area where sheets do not pass over) excessively rises, which may result in poor fixing. In addition, the heat receiving member may get damaged depending on a material of the heat receiving member.
From the above reason, control for preventing temperature rise at an end portion of the heat receiving member has been made. For an example, an apparatus is configured to prevent a temperature rise at an end portion of the heat receiving member by increasing a sheet supply interval when a temperature of the heat receiving member sensed at an area where no sheet passes exceeds a specified threshold value.